06 450 jetting with an AP Modded carb

djtroy

I know there are many threads on jetting but I was wondering what you guys think jetting might be if I have the AP Mod done to my carb and I live in Florida. I noticed recently it has a bit of a backfire. I noticed the screw that goes into the carb that holds the idle screw bracket to the carb is missing I don't know if this has anything to do with the backfiring but it was the only time I noticed it. So maybe if I replace that screw it might go away but I doubt it. I will keep my eye on it and see if its still backfiring after i replace it. I think I read that backfiring is caused from a lean condition, perhaps this is whats going on with mine. Correct me if I am wrong.

Is jetting these things any harder than tearing apart a 2 stroke carb to jet it? This is my first dance with a 4 stroke.

kxman

Wireing the AP will not really have an effect on you jetting set up. Put in a 45 pilot and a 168 main and get a zip-ty extended fuel screw. Start with the fuel screw out 1.75 turns and adjust from there. These are just suggestions as there are many variables in jetting. Don't worry about a little bit of popping on decel. Oh, and that screw that goes through the float bowl and holds you idle adjuster bracket on, replace it of course.

djtroy

Wireing the AP will not really have an effect on you jetting set up. Put in a 45 pilot and a 168 main and get a zip-ty extended fuel screw. Start with the fuel screw out 1.75 turns and adjust from there. These are just suggestions as there are many variables in jetting. Don't worry about a little bit of popping on decel. Oh, and that screw that goes through the float bowl and holds you idle adjuster bracket on, replace it of course.

Thank you for the tips I will let you know how it works out. How hard is it to work on the carb compared to 2 stroke carbs?

kxman

Well, the basics are the same. Of course you do have some added complexity due to the AP circuit, and as you will find out they are more difficult to access. This was compounded by the aluminum frame. The pilot and main jets I had left over from my KX250 work on this carb.

red7

Well, the basics are the same. Of course you do have some added complexity due to the AP circuit, and as you will find out they are more difficult to access. This was compounded by the aluminum frame. The pilot and main jets I had left over from my KX250 work on this carb.

That last sentence was a pleasant surprise as I was just about to do a search to find out if my jets will work on a buddies KX250.